As an example of conventional aesthetic counseling methods, an average face prepared for each age group and the face of a subject, which is a customer, are compared, and by using an index formed by the results of examining the comparison, changes in facial features of the subject with age are qualitatively obtained. However, such an index is not quantitatively obtained, and quantitative judgment as to the degree of change in the facial features of the subject in relation to aging largely depends on the personal viewpoint of a counselor.
For middle-aged and elderly females and many other subjects, “looking younger” is the first “impression that they want to give to others.” In particular, these middle-aged and elderly people, regardless of gender, are highly interested in “keeping themselves looking younger than his or her actual age.”
Thus, it is considered that it is highly useful to quantify factors in the face (facial feature) of a subject that determines the impression of aging. This is because it is considered that, by performing quantification as to whether the apparent age, determined by the impression based on the facial shape of the subject, is younger than the actual age, it is possible to provide aesthetic treatments such as makeup and aesthetic massage that, at the finish of the treatment, the subject can be highly satisfied with.
Further, other than “looking younger,” young females want to appear to have a “small face” and an “adult face” as the “impression that they want to give to others.” The term “adult face” is opposed to the term “baby face,” and represents a degree to which the facial feature looks adult. The degree to which they have an adult face and the apparent age is different ideas. The apparent age relates to an index indicating how old the subject looks. The degree of adult face is irrelevant to the apparent age, and relates to an index indicating whether the facial feature of the subject looks adult-like or child-like.
Patent Document 1 describes a method of estimating a change in the subject's face with age using a two-dimensional image of the face of a subject. Patent Document 1 describes generating an average face for each age group on the basis of a large number of two-dimensional images, setting, as factors, the size or position of, for example, the facial form, the upper eyelid, the angulus oris, the nasolabial sulcus, and the lower jaw, and comparing the average face and the subject's face.
Patent Document 2 describes measuring three-dimensional form information on the head including the face using a device, calculating a distribution of curvature of the curved surface at each point on the face, and evaluating the form of the face.
Patent Document 3 describes a calculation method of generating a homologous model in which three-dimensional form models of the heads of humans each has the number of data points (number of vertexes) and topology consistent with each other, so that multivariate analysis such as principal component analysis can be performed with the relatively small amount of data. In other words, Patent Document 3 relates to a method of generating a homologous model.
Patent Document 4 describes applying the principal component analysis to the form feature vectors of the two-dimensional image of the front view of the subject's face to obtain the first principal component, changing the eigenvalues of this first principal component, thereby reconfiguring the image. With this method, it is possible to change the apparent age and facial expression of the image of the subject's face, and the body shape of the subject.